Aqueous composition containing H2O2, acids and Ag, preparation method therefor and use thereof for disinfection, hygiene and/or pollution control

ABSTRACT

The present invention relates to an aqueous decontaminating composition comprising 
     (A) an amount of H 2 O 2  less than or equal to 60% by weight, based on the total weight of said composition; 
     (B) an RCO 3 H/RCO 2 H mixture, where R is methyl or ethyl, as indicated above, said mixture being present in an amount such that the weight ratio of said mixture to the hydrogen peroxide is between 0.15/1 and 0.85/1; 
     (C) a silver component as a source of Ag ions, selected from the group consisting of silver salts and complexes, said silver component being present in an amount such that the weight ratio of said silver component to the hydrogen peroxide is between 0.0005/1 and 0.015/1; 
     (D) a stabilizer present in an amount such that the weight ratio of said stabilizer to the hydrogen peroxide is between 0.0005/1 and 0.025/1; and 
     water to make up to 100% by weight. It further relates to the method of preparation and to the use of said composition.

This application is a 371 of PCT/FR95/01690, filed on Dec. 18, 1995.

FIELD OF THE INVENTION

The present invention relates to an aqueous disinfecting and cleaningcomposition based on H₂O₂, acids and Ag, as a novel industrial product.

It further relates to the method of preparation and to the use of thiscomposition on the one hand in the field of disinfection and/or hygiene,especially for disinfecting or sterilizing hospital and industrialpremises, surfaces of various materials, storage containers, pipelines,harvests, foodstuffs and drinking water, and on the other hand in thefield of pollution control, especially for controlling pollution in themining industries (in particular in the prevention of acid mine drainageand the destruction of cyanides in the soil).

PRIOR ART

In the field of disinfection, several technical solutions are knownwhich utilize H₂O₂: some involve an aqueous composition containing H₂O₂,a percarboxylic acid (RCO₃H, where R is a C₁-C₂-alkyl group) and thecorresponding carboxylic acid (RCO₂H), and others involve an aqueouscomposition containing H₂O₂ and silver in the form of a salt or complex.

Thus EP-A-0 370 850 has disclosed an aqueous composition comprising H₂O₂(6-8% by weight, based on the total weight of said composition), CH₃CO₃H(0.1 to 1% by weight) and CH₃CO₂H (2 to 10% by weight) as a hygieneagent for the disinfection of hemodialysis equipment; this compositioncan be diluted with water before use.

EP-A-0 193 416 has disclosed an aqueous composition comprising H₂O₂ (1to 8% by weight), CH₃CO₃H (0.005 to 0.1% by weight) and CH₃CO₂H in theamount necessary to attain the equilibrium of the system according tothe following equation:

H₂O₂+CH₃CO₂H←→CH₃CO₃H+H₂O  (1a)

said composition being used for rendering contact lenses aseptic.

In its only Example, EP-B-0 087 343 (see top of column 6) has disclosedan aqueous composition comprising H₂O₂(19.9% by weight), CH₃CO₃H (2% byweight), CH₃CO₂H (6.1% by weight), HNO₃ (8.0% by weight) as apreservative, hydroxyethanediphosphonic acid (0.3% by weight) as astabilizer and/or corrosion inhibitor, and H₂O (63.7% by weight), thiscomposition being presented as a disinfecting product which is lesscorrosive towards metals (especially steel) than Javelle water, on theone hand, and the acid CH₃CO₃H, on the other.

FR-A-2 321 302 has disclosed an aqueous composition comprising H₂O₂(25-40% by weight), RCO₃H [and/or RCO₂H] (0.5-20% by weight), phosphonicacid (0.25-10% by weight) and H₂O (to make up to 100% by weight) as amicrobicidal product, the molar ratio H₂O₂/RCO₃H being greater than orequal to 2/1 and preferably between 3/1 and 50/1. The phosphonic acidcomponent present in the aqueous composition according to FR-A-2 321 302is a hydroxyalkylpolyphosphonic acid, aminoalkylpolyphosphonic acid orpolyaminoalkylenepolyphosphonic acid compound or an Na, K, ammonium orω-hydroxyalkylammonium salt, this phosphonic acid component actingprincipally as a corrosion inhibitor.

It is known that a percarboxylic acid is prepared according to equation(1):

H₂O₂+RCO₂H←→RCO₃H+H₂O  (1)

and that, to stabilize concentrated aqueous solutions of RCO₃H, it isrecommended, especially by FR-A-2 309 531, FR-A-2 321 301 and EP-A-0 024219, to incorporate H₂O₂ into said compositions. In practice, in thecase of an acid compound RCO₃H in aqueous solution, an aqueouscomposition is ultimately obtained which comprises a mixture of H₂O₂,RCO₃H and RCO₂H according to equilibrium equation (1) given above.

U.S. Pat. No. 3,035,698, on the other hand, has disclosed an aqueouscomposition comprising H₂O₂ and Ag⁺ ions as a disinfecting product.However, when the hydrogen peroxide in an aqueous mixture of H₂O₂+Ag⁺ isconcentrated, there is a considerable risk of explosion. To limit thisrisk, FR-A-2 597 347 envisages a preparative technique which utilizes astrong mineral acid (especially phosphoric acid, nitric acid,hydrobromic acid, hydrochloric acid, sulfuric acid or boric acid) and astabilizing organic acid (especially tartaric acid, citric acid, maleicacid, malonic acid, 6-acetamidohexanoic acid, hippuric acid oracetoxybenzoic acid).

More precisely, according to FR-A-2 597 347, the method of preparing anaqueous concentrate containing H₂O₂+Ag⁺ comprises the following steps:

mixing a strong mineral acid (pH<1.6) with a silver salt or a silvercomplex at a temperature of 50-60° C., the molar ratio strong mineralacid/silver component being greater than or equal to 1;

cooling the resulting mixture to a temperature of 25-30° C. and adding astabilizing organic acid, optionally together with gelatin; and

incorporating H₂O₂ into the resulting mixture.

The technical solutions of the prior art, which involve an aqueouscomposition comprising a mixture of H₂O₂+RCO₃H+RCO₂H or a mixture ofH₂O₂+Ag⁺, are found to have an inadequate disinfecting effect(bactericidal, fungicidal, virucidal, algicidal or parasiticidaleffect). The following has been observed in particular:

(α) When aqueous compositions corresponding to said technical solutionsof the prior art are sprayed into enclosed spaces containing harmful orundesirable strains, the difference between the decimal logarithm of theconcentration of said strains at time T=0 and the decimal logarithm ofthe concentration of the same strains at time T=2 h is not alwaysgreater than or equal to 3 for molds or greater than or equal to 4 forbacteria.

In other words, if [S]_(T=0) is the concentration (number of germs perml) of a given strain at time T=0 and [S]_(T=2h) is that of the samestrain at time T=2 h after exposure to a sprayed aqueous composition for2 h, the technical solutions of the prior art produce a result (ΔR)given by the relationship

ΔR=log₁₀([S]_(T=0))−log₁₀([S]_(T=2h))  (2)

which is such that, very often,

ΔR≦3 for molds, and

ΔR≦4 for bacteria.

(β) There are strains, especially strains of Penicillium verrucosus,which resist the aqueous compositions of the technical solutions of theprior art comprising a mixture of H₂O₂+RCO₃H (especially CH₃CO₃H)+RCO₂H(especially CH₃CO₂H) or a mixture of H₂O₂+Ag⁺.

As far as pollution control is concerned, it should be pointed out thatthe mining industry has to deal with two major environmental problems:(i) leaching (solubilization) of the metals contained in the soils, dueto acid drainage and common to all types of mine, and (ii) contaminationof the soils by the cyanides originating particularly from the techniqueof gold extraction in gold mines and gold works.

Numerous minerals and metals present in mine soils, such as arsenic,selenium and aluminum, can be solubilized and can end up in thesubterranean waters and the environment due to acid drainage. The aciddrainage of rocks is the result of natural oxidation of thesulfur-bearing ores following their exposure to air and water. Theseoxidation reactions are often accelerated by certain microorganisms. Thechemical and biological reactions cause a lowering of the pH of thewater, which then has the property of mobilizing any heavy metal whichmay be present in the rock residues. If sufficient water is available,it will act as a vehicle and the resulting drainage may contain theproducts of the acid generation process, typically appreciable amountsof Al, Ca, Si, Mg, Na, K, Fe, other metals and sulfates. This phenomenoncauses a negative impact on the quality of the water infiltrating intothe environment. By way of example, as sulfur-bearing ores are presentthroughout the Canadian Shield and in coal mines, the leaching of metalsis a very widespread problem in the Canadian mining industries.

Acid generation is the result of a complex process involving a largenumber of chemical reactions. These reactions can be simply illustratedby the following example of the oxidation of pyrites (FeS₂), which isone of the most common sulfur-bearing ores.

The first important reaction is oxidation of the sulfur-bearing ore toferrous iron, sulfate ions and hydrogen (H⁺):

FeS₂+7/2O₂+H₂O→Fe²⁺+2 SO₄ ²⁻+2 H⁺  (2)

The dissolved iron, the sulfates and the hydrogen cause an increase inthe concentration of total dissolved solids and an increase in theacidity of the water. The rise in acidity is associated with a drop inpH. If the neighboring environment is sufficiently oxidizing, most ofthe ferrous iron will be oxidized to ferric iron (Fe³⁺):

Fe²⁺+¼O₂+H⁺→Fe³⁺+½ H₂O  (3)

At low pH, the ferric iron will precipitate in the form of Fe(OH)₃,leaving only a little Fe³⁺ in solution and lowering the pH at the sametime:

Fe³⁺+3 H₂O→Fe(OH)₃ (solid)+3 H⁺  (4)

Any Fe³⁺ ion formed in equation 3 and not precipitated in equation 4 canbe used to oxidize more pyrites:

FeS₂+14 Fe³⁺+8 H₂O→15 Fe²⁺+2 SO₄ ²⁻+16 H⁺  (5)

On the basis of these simplified reactions, acid generation, whereferric ions are formed and subsequently precipitated as Fe(OH)₃, can besummarized by combining equations 2, 3 and 4:

FeS₂+15/4 O₂+7/2 H₂O→Fe(OH)₃+2 SO₄ ²⁻+4 H⁺  (6)

Certain bacteria are found to be capable of accelerating several ofreactions 2-5, increasing the acid generation rate by a factor of up to5. Among these bacteria, strains of Thiobacillus ferrooxidans are knownto accelerate reactions 2, 3 and 5. It is known that Thiobacillusferrooxidans is particularly involved in the oxidation of pyrites andthat it is capable of accelerating the oxidation of the sulfides of As,Cu, Cd, Co, Ni, Sb, Mo, Pb and Zn, thereby increasing the rate or degreeof solubilization of these metals. Thus the presence of oxidized arsenic(AsO₄ ³⁻) in the environment is due to the solubilization ofsulfur-bearing ores such as arsenopyrite, realgar, orpiment, cobaliteand niccolite. There is therefore a need to prevent acid generation (andhence metal leaching and sulfate formation) by influencing the bacteria,such as Thiobacillus ferrooxidans, involved in the oxidation ofsulfides.

Furthermore, in the processes for the extraction of metals such as gold,the release of toxic cyanides into the mining residues and the wastewaters represents a major environmental problem. The waste waters can bepurified by chemical oxidation of the cyanides they contain using anoxidizing agent such as H₂O₂ or SO₂. On the other hand, nothing iscurrently being done to treat the soils containing cyanides—the goldmining industry is content for the cyanides to be destroyed by naturalatmospheric oxidation mechanisms. There is therefore an urgent need inthis area to clean the soils containing cyanides.

OBJECT OF THE INVENTION

According to a first feature of the invention, it is proposed to providea novel technical solution which makes it possible to overcome theaforementioned disadvantages of the technical solutions of the priorart. This novel technical solution involves an aqueous compositioncomprising a mixture of H₂O₂+RCO₃H+RCO₂H+Ag⁺, said mixture making itpossible to obtain, especially by spraying into an enclosed space, a ΔRvalue greater than 3 for molds and greater than 4 for bacteria afterexposure for 2 h.

According to a second feature of the invention, it is proposed toprovide, according to said technical solution, an aqueousdecontaminating (i.e. disinfecting and/or cleaning) compositioncomprising a mixture of H₂O₂, RCO₃H (where R is ethyl or, preferably,methyl), RCO₂H (where R is defined as indicated above), Ag (in the formof a salt or complex as a source of Ag⁺ ions) and H₃PO₄, in which thefour components hydrogen peroxide, percarboxylic acid, carboxylic acidcorresponding to said percarboxylic acid and Ag⁺ have a synergisticeffect in respect of the disinfecting and cleaning properties.

According to a third feature of the invention, it is proposed to providea method of preparing said aqueous decontaminating composition.

According to yet another feature of the invention, it is proposed to usesaid aqueous decontaminating composition (i) for disinfecting and/or“cold-sterilizing” in particular, or sterilizing at room temperature(10-25° C.), enclosed spaces (hospital, agricultural, industrial,household or transport premises), surfaces of various materials,instruments, storage containers, liquid pipelines, foodstuffs anddrinking water, and (ii) for cleaning mining sites in order to preventacid generation and/or to destroy the cyanides (by oxidation).

SUBJECT OF THE INVENTION

According to the novel technical solution of the invention, an aqueousdecontaminating composition is recommended, said composition, whichcontains H₂O₂ and a silver component in an acid medium, comprising

(A) an amount of H₂O₂less than or equal to 60% by weight, based on thetotal weight of said composition;

(B) an RCO₃H/RCO₂H mixture, where R is methyl or ethyl, said mixturebeing present in an amount such that the weight ratio of said mixture tothe hydrogen peroxide is between 0.15/1 and 0.85/1;

(C) a silver component as a source of Ag⁺ ions, selected from the groupconsisting of silver salts and complexes, said silver component beingpresent in an amount such that the weight ratio of said silver componentto the hydrogen peroxide is between 0.0005/1 and 0.015/1;

(D) a stabilizer present in an amount such that the weight ratio of saidstabilizer to the hydrogen peroxide is between 0.0005/1 and 0.025/1; and

water to make up to 100% by weight.

The method of preparing said aqueous decontaminating compositionaccording to the invention comprises steps consisting in

(1°) preparing an aqueous solution of the silver component which ispresent as a source of Ag⁺ ions;

(2°) introducing the stabilizer into said resulting solution obtained inthis way;

(30°) introducing said resulting solution obtained in this way into thehydrogen peroxide solution or introducing the hydrogen peroxide solutioninto said resulting solution;

(4°) introducing, into said resulting solution obtained in this way, anacid substance selected from the group consisting of RCO₃H, RCO₂H andmixtures thereof, i.e. RCO₃H+RCO₂H;

(5°) leaving said resulting solution obtained in this way until theequilibrium H₂O+RCO₂H←→RCO₃H+H₂O has been established; and

(60°) making up to 100% by weight with water.

The use of the aqueous decontaminating composition according to theinvention as a disinfecting product comprises

(i) a surface or volume treatment of the product to be disinfected ordecontaminated, at a temperature of between 0° C. and 50° C., preferablyat room temperature (RT) within the range 10° C. to 25° C., with saidaqueous disinfecting composition, optionally diluted, and then

(ii) the drying of said product treated in this way.

The use of said aqueous composition as a cleaning product comprises step(i) above, the drying of step (ii) taking place of its own accord atroom temperature.

The product to be disinfected comprises especially enclosed spaces(particularly hospital, agricultural and industrial premises), surfacesof various materials, instruments, storage containers, pipelines(especially pipelines for aqueous liquids such as water, milk, beer andfruit juice), foodstuffs, harvests, outdoor or greenhouse crops anddrinking water.

The product to be cleaned consists especially of soils and waste heapsin the mining industry.

DETAILED DESCRIPTION OF THE INVENTION

Hereafter, unless indicated otherwise, the respective amounts of theingredients of the aqueous decontaminating composition according to theinvention are expressed in % by weight and the dilutions of saidcomposition are expressed as the ratio initial volume/volume of theresulting diluted composition.

In general terms, the aqueous decontaminating composition according tothe invention has an H₂O₂ content which is less than or equal to 60% byweight, based on the weight of said composition. For said aqueouscomposition, the lowest antibacterial dose tested corresponds to a finaldilution of {fraction (5/10)}⁷ (containing 0.000025% by weight of H₂O₂);at this dose, the composition according to the invention providesantibacterial protection for at least 48 h (in the field ofbalneotherapy).

Consequently, in the vast majority of cases, the present inventionrecommends a composition which comprises 0.1 to 60% by weight of H₂O₂and which can be diluted at the appropriate time during use.

Hydrogen peroxide presents difficulties as regards transportation whenusing hydrogen peroxide solution with a high H₂O₂content, for example anH₂O₂ content greater than 16% or 8% by weight, depending on theregulations in several countries. If, from a practical point of view, itis advantageous to use hydrogen peroxide solution containing 50 to 70%by weight of H₂O₂ as a starting material, the aqueous disinfectingcomposition according to the invention should preferably have an H₂O₂content which is less than or equal to 8% by weight, so as to avoidspecial vented packaging to comply with the national regulations forrestricting transport, said packaging requiring qualified personnel touse it.

In practice, the aqueous decontaminating composition according to theinvention will have an H₂O₂ content of the order of 7.5-8% by weight andwill be diluted with water, at the time of use, down to a final H₂O₂concentration particularly of between 0.0000025 and 4% by weight.

As a variant, it is possible to market an optionally prediluted, aqueousdisinfecting or cleaning composition which is stabilized and contains1.5 to 8% by weight of H₂O₂, is ready to use and retains its efficacyfor at least two years.

In practice, the aqueous decontaminating composition according to theinvention will advantageously contain 7.5 to 8% by weight of H₂O₂ and,if appropriate, will be diluted with H₂O by the user.

The respective amounts of RCO₃H and RCO₂ H in the RCO₃H/RCO₂H mixtureare not critical. Given equilibrium reaction (1) above, it suffices tohave either H₂ ₂O and RCO₃H or H₂O₂ and RCO₂H together in H₂O in orderto produce a ternary mixture of H₂O₂+RCO₃H+RCO₂H, provided that H₂O₂ isin excess relative to the RCO₃H/RCO₂H pair. It therefore suffices, as itwere, to incorporate

(i) RCO₂H in the presence of H₂O₂, or

(ii) RCO₃H (which, in the concentrated state, generally contains H₂ ₂Oand RCO₂H according to documents FR-A-2 321 301 and FR-A-2 321 302 citedabove) into H₂O in order to produce the combination of H₂O₂+RCO₃H+RCO₂Hin equilibrium.

In the aqueous decontaminating composition according to the invention,the weight ratio of the RCO₃H/RCO₂H mixture to the hydrogen peroxide isbetween 0.15/1 and 0.85/1. In practice, this weight ratio willadvantageously be between 0.5/1 and 0.7/1.

In general terms, the CH₃CO₃H/CH₃CO₂H pair (i.e. R=methyl) is preferredto the CH₃CH₂CO₃H/CH₃CH₂CO₂H pair (i.e. R=ethyl) since the first pair ismore active than the second as a disinfecting/cleaning means in theaqueous composition according to the invention.

In increasing order of preference, the recommended silver component willbe a silver complex, a silver salt with an organic acid (especiallyCH₃CO₂Ag) or a silver salt with a mineral acid (especially Ag₂SO₄ andpreferably AgNO₃).

Silver oxides, Ag₂O and AgO, are unsuitable because they are notwater-soluble. If Ag₂O and/or AgO were used, it would be necessaryfirstly to solubilize them with a relatively large amount of a strongbase (NaOH or KOH) and then to increase the initial amounts of theRCO₃H/RCO₂H mixture (component B above), on the one hand, and those ofthe acid stabilizer (component D above), on the other, so as (α) toneutralize the strong base and (β) to have the required amounts ofcomponents B and D in the aqueous decontaminating composition.

In the aqueous decontaminating composition according to the invention,the weight ratio of the silver component to the hydrogen peroxide isbetween 0.0005/1 and 0.015/1. In practice, this weight ratio willadvantageously be between 0.0008/1 and 0.005/1 and preferably of theorder of 0.001/1.

The stabilizer, which is present (i) to protect the H₂O₂ and the Ag⁺ions during the preparation of the aqueous decontaminating compositionaccording to the invention and avoid any risk of explosion, especiallyfrom concentrated solutions of H₂O₂ and Ag⁺, and (ii) to preserve therequired concentrations between H₂O₂, CH₃CO₃H and Ag⁺ in saidcomposition until it is used, is selected from the group consisting ofmineral and organic acids. The most effective of these acids are strongmineral acids, the most valuable here being H₃PO₄, which is veryparticularly preferred.

In the aqueous decontaminating composition according to the invention,the weight ratio of the stabilizer to the hydrogen peroxide is between0.0005/1 and 0.025/1. In practice, this weight ratio will advantageouslybe between 0.0008/1 and 0.005/1 and preferably of the order of 0.001/1.

According to the invention, it is recommended advantageously to use thestabilizer in an amount which is substantially identical to or slightlygreater than that of the silver component.

The aqueous disinfecting composition according to the invention can alsocontain at least one component selected from the group consisting of

(E) a surfactant;

(F) a corrosion inhibitor; and

(G) a fragrance.

The surfactant used here is (i) an ionic or non-ionic surface-activecompound suitable in particular for contact with foodstuffs and, ifappropriate, suitable for oral administration with drinking water at theuse dose in question, or (ii) a mixture of such compounds.

Among the products suitable for this purpose, particular mention may bemade of alkylbenzenesulfonates, alkylsulfates and alkanesulfonates ofalkaline earth metals and (preferably) alkali metals (particularly Na orK), as well as polyethoxylated phosphoric acid alkyl esters and mixturesthereof.

In the aqueous decontaminating composition according to the invention,the weight ratio of the surfactant to the hydrogen peroxide is between0.00005/1 and 0.01/1. In practice, this weight ratio will advantageouslybe of the order of 0.005/1.

It is recommended to incorporate a corrosion inhibitor into the aqueousdecontaminating composition according to the invention, said corrosioninhibitor, at the dose use, being suitable for contact with foodstuffsand/or for oral administration with drinking water. As corrosioninhibitors which can be used for this purpose, particular mention may bemade of the aminophosphonic acids described in FR-A-2 321 302 citedabove, their sodium, potassium, ammonium and alkanolamine salts andmixtures thereof. Hydroxyethanediphosphonic,dimethylaminomethanediphosphonic andethylenediaminotetrakis(methylenephosphonic) acids, their Na, K, NH₄ ⁺or alkanolamine salts and mixtures thereof are particularly suitable forthe aqueous decontaminating composition according to the invention.1,2,3-Benzotriazole is also suitable as a corrosion inhibitor.

In practice, the corrosion inhibitor will be present at a lowconcentration in the aqueous decontaminating composition according tothe invention. When present, said corrosion inhibitor will be usedespecially in an amount such that the weight ratio of said corrosioninhibitor to the hydrogen peroxide is between 0.00005/1 and 0.03/1 andpreferably between 0.001/1 and 0.005/1. As the aqueous decontaminatingcomposition according to the invention contains corrosive acidsubstances, namely RCO₃H, RCO₂H and the stabilizing acid component ofitem D (H₃PO₄), it is important to limit the corrosion so that thecorrosion rate of steel or copper articles subjected to 200 immersioncycles in the aqueous decontaminating composition according to theinvention, followed by drying (without rinsing), or to 200 sprayingcycles with said composition, followed by drying at 15-35° C. (oven orstream of purified air; without rinsing with water), is less than 50μm/year.

In fact, as the corrosion of metal surfaces is principally the result ofa phenomenon called “pitting”, it is essential to avoid the formation ofsaid pits, where the germs which it is desired to eradicate would resideand develop.

The fragrant component of item (G) will be used in the aqueousdecontaminating composition in an amount which is less than or equal tothat of the corrosion inhibitor of item (F).

The water which forms part of the decontaminating composition accordingto the invention is advantageously a purified water, namely distilledwater, demineralized water or, preferably, deionized water. Here thedeionized water will preferably be a water having a resistivity greaterthan 10⁵ Ω/cm and preferably greater than 10⁶ Ω/cm.

The water optionally used to dilute said decontaminating compositionaccording to the invention will advantageously be purified water asindicated above.

The pH of the aqueous composition according to the invention (beforeuse) is generally between 1.5 and 4. It is regulated by means of thepreferred component D, H₃PO₄.

The aqueous decontaminating composition which is particularlyrecommended comprises

(A) 1.5 to 8% by weight of H₂O₂;

(B) 0.75 to 5.6% by weight of a mixture of RCO₃H and RCO₂H, where R isethyl or, preferably, methyl;

(C) 0.0012 to 0.04% by weight of a silver component selected from silvercomplexes and salts as a source of Ag⁺ ions;

(D) 0.0012 to 0.04% by weight of H₃PO₄;

(E) if appropriate, 0.0075 to 0.04% by weight of surfactant;

(F) if appropriate, 0.003 to 0.04% by weight of corrosion inhibitor;

(G) if appropriate, a fragrance; and

water (distilled, demineralized or deionized) to make up to 100% byweight.

A stock solution with an H₂O₂ content of the order of 7.5-8% by weightis recommended more particularly. This stock solution contains

(A) 7.5-8% by weight of H₂O₂;

(B) 4.5 to 4.8% by weight of a mixture of CH₃CO₃H+CH₃CO₂H;

(C) 0.008% by weight of AgNO₃;

(D) 0.008% by weight of H₃PO₄; and

water (distilled, demineralized or deionized) to make up to 100% byweight.

Said stock solution is then used

either as such or diluted with purified water to an H₂O₂ content of 1.5to 4% by weight;

or complemented with components (E), (F) and/or (G) and then, ifnecessary, diluted with purified water to an H₂O₂ content of 1.5 to 4%by weight;

or complemented with mixture (B) of CH₂CO₃H+CH₃CO₂H until the content ofsaid mixture in the aqueous decontaminating composition is 5.6% byweight, the resulting composition then being diluted with purified wateras indicated above, if necessary;

or complemented on the one hand with mixture (B) and on the other handwith components (E), (F) and/or (G), and then, if appropriate, dilutedwith water as indicated above.

When the preparative method referred to above in the section “Subject ofthe invention” is carried out, steps (1°) and particularly (2°) to (4°)and (6°) are performed with stirring. In practice, steps (3°) and (4°)are carried out at a temperature less than or equal to 30° C. andpreferably at a temperature less than or equal to 25° C., and step (2°)is carried out at a temperature less than or equal to 60° C.

In step (1°), the source of Ag⁺ ions will preferably be AgNO₃. In step(2°), a concentrated aqueous solution of phosphoric acid, in particulara commercial solution containing 85% by weight of H₃PO₄, may be used asthe stabilizer.

In step (3°), hydrogen peroxide solution with an H₂O₂ content greaterthan 8% by weight and less than or equal to 70% by weight is used;either the solution obtained in step (2°) is introduced into saidhydrogen peroxide solution, or said hydrogen peroxide solution isintroduced into the solution obtained in step (2°); each of theseintroductions is carried out slowly (especially at a rate of 1 to 5liters of solution introduced in 20-60 minutes), with stirring and withcooling to a temperature less than or equal to 30° C. and preferably toa temperature less than or equal to 25° C.

In step (4°), the acid substance (RCO₃H, RCO₂H or the mixture ofRCO₃H+RCO₂H) is introduced into the solution obtained in step (3°),under the same conditions as in said step (3°) as regards theintroduction rate, temperature and stirring.

In step (5°), the solution obtained in step (4°) is left to stand forabout 48 h at a temperature less than or equal to 30° C. and preferablyat a temperature less than or equal to 25° C., so that the equilibriumof equation (1) is established. Step (5°) is advantageously carried outin the dark.

As indicated above, the water used to prepare the aqueousdecontaminating composition according to the invention, especially insteps (1°) and (6°), is purified water, i.e. distilled, demineralized ordeionized water.

Components (E), (F) and/or (G) are introduced in appropriate mannerbetween step (1°) and step (6°). As a variant, each of these ingredientscan be incorporated at the end of step (6°).

The aforementioned stock solution containing 7.5-8% by weight of H₂O₂ isprepared by a particular method which comprises steps consisting in

(1°) preparing a solution of AgNO₃ in part of the total amount of waterrequired to produce said aqueous disinfecting composition;

(2°) introducing, into the resulting solution obtained in this way, anaqueous solution of phosphoric acid containing 85% by weight of H₃PO₄;

(3°) introducing the resulting solution obtained in this way into anaqueous solution of hydrogen peroxide containing 50 to 60% by weight ofH₂O₂, with stirring, at a temperature of between 0° C. and 25° C. andpreferably at a temperature of between 4° C. and 15° C., and withintroduction of the solution obtained in step (2°) at a rate of between3 and 6 l/h;

(4°) introducing the acid substance CH₃CO₂H into the resulting solutionobtained in this way, with stirring, at a temperature of between 0° C.and 25° C. and preferably at a temperature of between 4° C. and 15° C.,and with introduction of the acid substance CH₃CO₂H at a rate of between3 and 6 l/h;

(5°) leaving the resulting solution obtained in this way to stand for 48h, in the dark, at a temperature of between 0° C. and 25° C. andpreferably at a temperature of between 4° C. and 15° C., so that theequilibrium

H₂O₂+CH₃CO₂H←→CH₃CO₃H+H₂O

is established; and

(6°) adding the remaining water to make up to 100% by weight.

In step (4°) of the preparation of the stock composition, the acid canbe introduced in the form of an aqueous solution.

When the aqueous decontaminating composition according to the inventionis employed as a disinfecting composition, as is generally the case, itis used (i) as prepared, or (ii) at a rate of at least 5 ml of saidcomposition for a volume of 1 m³ or surface of 1 m² to be treated, saidcomposition being diluted if appropriate.

As regards the use of the aqueous composition according to the inventionas a disinfectant, the following is more particularly recommended:

(α) immersion of the product to be treated (which has advantageouslybeen washed beforehand) in an aqueous decontaminating compositioncontaining 1.5 to 4% by weight of HO₂O₂;

(β) spraying of an aqueous disinfecting composition containing 2 to 4%by weight of H₂O₂ onto a surface to be treated (this is the case ofoutdoor crops) at a rate of 5 to 20 liters of said composition perhectare;

(γ) spraying of an aqueous disinfecting composition containing 2 to 8%by weight of H₂O₂ into a volume to be treated (this is the case of foodharvests in silos) at a rate of 0.5 to 4 liters of said composition perm³; or

(δ) incorporation of an aqueous disinfecting composition containing 16to 50% by weight of H₂O₂ into the water to be treated (this is the caseparticularly of swimming pool water or drinking water) at a rate of 5 to150 ml of said composition per 1 m³ of water to be treated (5 to 150 mlcorresponding to a final use concentration of 0.00008% by weight to0.0075% by weight of H₂O₂); in particular, for the disinfection ofdrinking water, about 20 ml/m³ will be used (i.e. a final useconcentration of the order of 0.001% by weight of H₂O₂).

The aqueous disinfecting composition according to the invention isespecially useful for:

(a) the disinfection and hygiene of hospital premises and industrialpremises (milk dairies, cheese dairies, malt houses, breweries,greenhouses, cowsheds, hen houses, stables, packaging lines forfoodstuffs, drinks or drugs, interiors of aeroplanes and boats) and thecontents of said premises, especially the equipment or instrumentsequipping said premises or used therein;

(b) the disinfection and hygiene of storage containers (especiallysilos) and pipelines for conveying liquid or solid products such asfoodstuffs (sugar, tea, coffee, cereals, drinks);

(c) the disinfection and hygiene of swimming pools and the contents ofthe aforementioned storage containers and pipelines;

(d) the disinfection of drinking water; or

(e) the protection of outdoor crops (cereals, tomatoes, forests, bananaplantations, orchards, etc.), by virtue of its bactericidal, fungicidal,sporicidal, virucidal and antiparasitic properties.

When employed as a cleaning composition, the composition according tothe invention is used either by being sprayed into the volume to betreated or onto a surface of said volume, or else by being stirred in.

In practice, the starting composition, like the aforementioned stockcomposition, will contain 7.5 to 8% by weight of H₂O₂ and will bediluted before use to a final use dilution of less than {fraction(1/100)} (preferably a dilution of {fraction (5/1000)} to {fraction(5/10,000)} and particularly preferably of {fraction (1/1000)}).

The cleaning composition according to the invention is mainly effectivein mining sites, especially for eliminating or substantially reducing(i) acid generation (particularly from sulfur-bearing ores) and (ii)cyanides (particularly in the case of gold mines and gold extractionplants).

Best Mode

The best mode of carrying out the invention consists in using a stockcomposition which, as indicated above, contains

(A) 7.5-8% by weight of H₂O₂;

(B) 4.5 to 4.8% by weight of a mixture of CH₃CO₃H+CH₃CO₂H;

(C) 0.008% by weight of AgNO₃;

(D) 0.008% by weight of H₃PO₄; and

distilled, demineralized or deionized water to make up to 100% byweight.

This stock composition is then complemented with components (E), (F)and/or (G) mentioned above and, if appropriate, components (B), (C) or(D).

Other advantages and characteristics of the invention will be understoodmore clearly from the following description of practical Examples andcomparative experiments. Of course, these data taken as a whole do notin any way imply a limitation but are given by way of illustration.

In these experiments, the “IP” strains used are those which weresupplied by the Collection Nationale de Cultures de Microorganismes(CNCM) administered by the Institut Pasteur in Paris.

EXAMPLES 1-5

The formulations of the Examples (Ex. 1-Ex. 5) according to theinvention, and the formulations of the Comparative Examples according tothe prior art without silver component (A1-A5) or without theRCO₃H/RCO₃H mixture (B1-B5), have been collated in Table Ia(CH₃CO₂H/CH₃CO₃H pair) and Table Ib (EtCO₂H/EtCO₃H pair) below,composition B4 of Table Ib being identical to that of composition B1 ofTable Ia, and the water present in these formulations (not mentioned insaid Tables Ia and Ib) representing the amount required to make up to100% by weight.

TABLE Ia Formulations (% by weight) of the ingredients other than thewater Mixture of Corrosion CH₃CO₂H + Surfactant inhibitor Product H₂O₂CH₃CO₃H AgNO₃ H₃PO₄ (a) (b) Ex. 1 8 4.8 0.008 0.008 0.04 0.032 A1 8 4.8— 0.008 0.04 0.032 B1 8 — 0.008 0.008 0.04 0.032 Ex. 2 8 5.6 0.005 0.0050.04 0.032 A2 8 5.6 — 0.005 0.04 0.032 B2 8 — 0.005 0.005 0.04 0.032 Ex.3 7.75 4.5 0.002 0.004 0.02 0.02 A3 7.75 4.5 — 0.004 0.02 0.02 B3 7.75 —0.002 0.004 0.02 0.02 Notes: see Table Ib

TABLE Ia Formulations (% by weight) of the ingredients other than thewater Mixture of Corrosion CH₃CO₂H + Surfactant inhibitor Product H₂O₂CH₃CO₃H AgNO₃ H₃PO₄ (a) (b) Ex. 1 8 4.8 0.008 0.008 0.04 0.032 A1 8 4.8— 0.008 0.04 0.032 B1 8 — 0.008 0.008 0.04 0.032 Ex. 2 8 5.6 0.005 0.0050.04 0.032 A2 8 5.6 — 0.005 0.04 0.032 B2 8 — 0.005 0.005 0.04 0.032 Ex.3 7.75 4.5 0.002 0.004 0.02 0.02 A3 7.75 4.5 — 0.004 0.02 0.02 B3 7.75 —0.002 0.004 0.02 0.02 Notes: see Table Ib

EXAMPLE 6

A concentration composition according to the invention was preparedwhich comprised:

H₂O₂ 50% by weight mixture of CH₃CO₂H + CH₃CO₃H 30% by weight AgNO₃0.05% by weight H₃PO₄ 0.05% by weight surfactant 0.25% by weightcorrosion inhibitor 0.20% by weight H₂O to make up to 100% by weight

This composition is diluted to the required H₂O₂ concentration at thetime of use.

EXAMPLE 7

A stock cleaning composition according to the invention was preparedwhich comprised:

H₂O₂ 7.8% by weight mixture of CH₃CO₂H + CH₃CO₃H 4.7% by weight AgNO₃0.008% by weight H₃PO₄ 0.008% by weight surfactant 0.04% by weight H₂Oto make up to 100% by weight

This stock composition is diluted to a final use dilution of less than{fraction (1/100)} at the time of use.

Analogous compositions A7 and B7 were likewise prepared for comparison,said compositions differing from Ex. 7 only in the absence of AgNO₃(composition A7) or in the absence of the mixture of CH₃CO₂H+CH₃CO₃H(composition B7).

Experiments I

The bactericidal, fungicidal and sporicidal activities of thecompositions according to the invention were measured, against thecomparative compositions, by spraying according to French Standard AFNORNF 72 281 (as revised in December 1989) under the following operatingconditions:

Spraying apparatus AEROBRUMEUR ® type H Output 16 ml/m³ Amount of testproduct 540 ml Diffusion time of the test product (i.e. composition) 12minutes Experimental enclosure volume 33 m³ temperature 23-24° C.relative humidity 85% (initial), 80% (final) Support microscope slidesfor bacteriology or mycology Distance of the support 1.2 m from thesource Exposure time of the support 2 h Recovery liquid steriledistilled water + TWEEN ® 80 (0.5% by weight) Volume of the recoveryliquid 100 ml Membrane rinsing volume 100 ml Number of rinses 3

The results obtained have been collated in Tables IIa to IIe below,which show the concentrations of the test products (i.e. compositionsEx. 1-Ex. 5, A1-A5 and B1-B5) after dilution with deionized water.

TABLE IIA Ex. 1 A1 B1 dilution: 1/5 dilution: 1/5 dilution: 1/5 Strain(1) (2) (3) (2) (3) (2) (3) Staphylococcus 1.8 × 10⁶ 0 6.25 0 6.25 06.25 aureus IP 52 154 Pseudomonas 1.5 × 10⁶ 0 6.17 1.9 × 10 4.90 2.1 ×10 4.85 aeruginosa IP A22 Enterococcus 1.6 × 10⁵ 0 5.20 10 4.20   9 × 103.25 faecium IP 5 855 Mycobacterium 1.3 × 10⁵ 0 5.11   2 × 10 3.81 1.9 ×10 3.84 smegmatis IP 7 326 Candida 1.9 × 10⁵ 0 5.27 1.8 × 10 4.02 1.5 ×10 4.10 albicans IP 1180 79 Penicillium 1.5 × 10⁵ 0 5.17  2.3 × 10² 2.81 2.7 × 10² 2.74 verrucosum IP 1186 79 spores of Bacillus 3.9 × 10³ 03.59 8.1 × 10 1.69 8.4 × 10 1.67 subtilis var. Niger IP 7 718 (a) Notes:(1) number of germs (or spores)/ml at time T = 0, i.e. [S]_(τ=0) (2)number of germs (or spores)/ml at time T = 2 h, i.e. [S]_(τ=2h) (3)germicidal (or sporicidal) activity, i.e. ΔR = log([S]_(τ=0)) −log([S]_(τ=2h))

TABLE IIb Ex. 2 A2 B2 dilution: ½ dilution: ½ dilution: ½ Strain (1) (2)(3) (2) (3) (2) (3) Staphylococcus 1.8 × 10⁶ 0 6.25 0 6.25 0 6.25 aureusIP 52 154 Pseudomonas 1.5 × 10⁶ 0 6.17 0 6.17 0 6.17 aeruginosa IP A22Enterococcus 1.6 × 10⁵ 0 5.20 0 5.20 5 4.61 faecium IP 5 855Mycobacterium 1.4 × 10⁵ 0 5.14 0 5.14 10 4.14 smegmatis IP 7 326 Candida1.9 × 10⁵ 0 5.27 5 4.58 10 4.27 albicans IP 1180 79 Penicillium 1.5 ×10⁵ 0 5.17    2 × 10² 2.87  2.3 × 10² 2.81 verrucosum IP 1186 79 sporesof 3.9 × 10³ 0 3.59 4.8 × 10 1.91 5.1 × 10 1.89 Bacillus subtilis var.Niger IP 7 718 (a) Notes: (1) number of germs (or spores)/ml at time T =0, i.e. [S]_(τ=0) (2) number of germs (or spores)/ml at time T = 2 h,i.e. [S]_(τ=2h) (3) germicidal (or sporicidal) activity, i.e. ΔR =log([S]_(τ=0)) − log([S]_(τ=2h))

TABLE IIc Ex. 3 A3 B3 dilution: 1/10 dilution: 1/10 dilution: 1/10Strain (1) (2) (3) (2) (3) (2) (3) Staphylococcus 2.1 × 10⁶ 10  5.32 1.1× 10² 4.28 1.2 × 10² 4.25 aureus IP 52 154 Pseudomonas 1.4 × 10⁶ 10 5.14 3.5 × 10  3.60 3.7 × 10  3.58 aeruginosa IP A22 Enterococcus 1.3 ×10⁵ 0 5.11 10² 3.11 1.7 × 10² 2.88 faecium IP 5 855 Hycobacterium 1.5 ×10⁵ 0 5.17 1.9 × 10² 2.89 2.2 × 10² 2.87 smegmatis IP 7 326 Candida 1.7× 10⁵ 10 4.23 2.8 × 10² 2.78 3.1 × 10² 2.73 albicans IP 1180 79Penicillium 1.1 × 10⁵ 1.3 × 10 3.82 6.7 × 10² 2.21 1.1 × 10⁵ 2.00verrucosum IP 1186 79 spores of 4.2 × 10⁵ 0 3.62 1.3 × 10² 1.51 1.9 ×10² 1.34 Bacillus subtilis var. Niger IP 7 718 (a) Notes: (1) number ofgerms (or spores)/ml at time T = 0, i.e. [S]_(τ=0) (2) number of germs(or spores)/ml at time T = 2 h, i.e. [S]_(τ=2h) (3) germicidal (orsporicidal) activity, i.e. ΔR = log([S]_(τ=0)) − log([S]_(τ=2h))

TABLE IId Ex. 4 A4 B4 = B1 dilution: 1/5 dilution: 1/5 dilution: 1/5Strain (1) (2) (3) (2) (3) (2) (3) Staphylococcus   2 × 10⁶ 0 6.30 06.30 0 6.30 aureus IP 52 154 Pseudomonas 1.5 × 10⁶ 0 6.17 2.11 × 10 4.85 2.1 × 10 4.85 aeruginosa IP A22 Enterococcus 1.6 × 10⁵ 0 5.20 1.1 ×10 4.16   9 × 10 3.25 faecium IP 5 855 Mycobacterium 1.3 × 10⁵ 0 5.112.2 × 10 3.77 1.9 × 10 3.84 smegmatis IP 7 326 Candida 1.8 × 10⁵ 0 5.251.9 × 10 3.98 1.5 × 10 4.08 albicans IP 1180 79 Penicillium 1.3 × 10⁵ 05.11  2.7 × 10² 2.68  2.6 × 10² 2.70 verrucosum IP 1186 79 spores of 3.9× 10³ 0 3.59  9 × 10 1.64 8.4 × 10 1.67 Bacillus subtilis var. Niger IP7 718 (a) Notes: (1) number of germs (or spores)/ml at time T = 0, i.e.[S]_(τ=0) (2) number of germs (or spores)/ml at time T = 2 h, i.e.[S]_(τ=2h) (3) germicidal (or sporicidal) activity, i.e. ΔR =log([S]_(τ=0)) − log([S]_(τ=2h))

TABLE IIe Ex. 5 A5 B5 dilution: 1/10 dilution: 1/10 dilution: 1/10Strain (1) (2) (3) (2) (3) (2) (3) Staphylococcus 1.9 × 10⁶ 1.1 × 105.16 1.4 × 10² 4.06 1.1 × 10² 4.16 aureus IP 52 154 Pseudomonas 1.5 ×10⁶ 10  5.17 3.7 × 10  4.61 1.5 × 10  4.00 aeruginosa IP A22Enterococcus 1.7 × 10⁵ 0 5.23 1.2 × 10² 3.16 1.5 × 10² 3.06 faecium IP 5855 Mycobacterium 1.3 × 10⁵ 0 5.11   2 × 10² 2.51 1.7 × 10² 2.88smegmatis IP 7 326 Candida 1.9 × 10⁵ 2 4.97 3.1 × 10² 2.00   3 × 10³2.80 albicans IP 1180 79 Penicillium 1.5 × 10⁵ 1.1 × 10 4.13 6.6 × 10²2.36 10³ 2.17 verrucosum IP 1186 79 spores of 4.1 × 10³ 0 3.61 1.4 × 10²1.47 1.8 × 10² 1.36 Bacillus subtilis var. Niger IP 7 718 (a) Notes: (1)number of germs (or spores)/ml at time T = 0, i.e. [S]_(τ=0) (2) numberof germs (or spores)/ml at time T = 2 h, i.e. [S]_(τ=2h) (3) germicidal(or sporicidal) activity, i.e. ΔR = log([S]_(τ=0)) − log([S]_(τ=2h))

The results in Tables IIa to IIe show that (i) in contrast tocompositions A1-A5 and B1-B5, the compositions according to theinvention are all fungicidal towards strains of Penicillium verrucosum,irrespective of the dilution, and (ii) at a given dilution, thecompositions according to the invention are always more effective thancompositions A1-A5 and B1-B5. These results further illustrate thesynergistic effect of the combination of H₂O₂+RCO₂H/RCO₃H mixture+silvercomponent.

Experiments II

The antiparasitic activity of the compositions according to theinvention (Ex. 1-Ex. 5) was studied using parasites responsible forschistosomiasis, namely strains of Schistosoma haematobium (bladderschistosomiasis) and of Schistosoma mansoni (intestinalschistosomiasis).

At time T=0, 10 ml of the undiluted test compositions are introducedinto flat-bottomed vessels of the Petri dish type, each containing 90 mlof nutrient medium and 8 to 10 parasite larvae. The number of livelarvae is measured at time T=0.5 h.

The results obtained are collated in Table III below:

TABLE III Number of live larvae Schistosoma haematobium Schistosomamansoni Product T = 0 T = 0.5 h T = 0 T = 0.5 h Ex. 1 10 0 8 0 A1 10 3 82 B1 10 3 8 3 Ex. 2 10 0 8 0 A2 10 3 8 2 B2 10 3 8 2 Ex. 3 8 8 0 0 A3 88 2 2 B3 8 8 3 2 Ex. 4 8 1 8 0 A4 8 2 8 2 B4 8 2 8 2 Ex. 5 8 0 8 0 A5 82 8 2 B5 8 2 8 3

The results in Table III show on the one hand the value of compositionsEx. 1-Ex. 5 according to the invention compared with compositions A1-A5and B1-B5, and on the other hand the synergistic effect of thecombination of H₂O₂+RCO₂H/RCO₃H mixture+silver component.

Experiments III

Experiments were carried out according to French Standard AFNOR NF T 72180 (as amended in December 1989) in order to assess the virucidalproperties of the compositions according to the invention (Ex. 1-Ex. 5)compared with the compositions of the prior art (A1-A5 and B1-B5).Briefly, the viral suspensions are brought into contact for 15, 30 and60 minutes, at 20° C., with each test composition (i.e. “product”)diluted with a phosphate buffer, and the titer of each viral suspensionis then measured after the virucidal activity of said composition hasbeen stopped by rapid dilution or, preferably, by molecular sieving. Thecontrols received the phosphate buffer only.

Under these operating conditions, a test composition is said to bevirucidal if it reduces the population of the virus in question by afactor of at least 10,000 (i.e. reduces the viral titer by a value of atleast 4) compared with the control experiments.

The results obtained (mean of 5 measurements) are collated in TablesIVa, IVb and IVc below, the viral strains used being as follows:

Orthopoxvirus (vaccinia virus),

Adenovirus (human adenovirus type 5) and

Poliovirus (poliomyelitis virus 1, SABIN strain).

TABLE IVa Viral strain: Orthopoxvirus Product Viral titer, i.e.log([S]_(T=X)) (dilution) T = 0.25 h T = 0.5 h T = 1 h Control T = 1 hEx. 1 ({fraction (9/10)}) ≦2.34 ≦2.34 ≦2.34 7.82 A1 ({fraction (9/10)})≦2.34 ≦2.34 ≦2.34 B1 ({fraction (9/10)}) ≦2.34 ≦2.34 ≦2.34 Ex. 1 (½)≦2.34 ≦2.34 ≦2.34 7.82 A1 (½) 5.21 ≦2.34 ≦2.34 B1 (½) 6.12 4.15 ≦2.34Ex. 1 ({fraction (1/10)}) 3.14 ≦2.34 ≦2.34 7.82 A1 ({fraction (1/10)})7.60 6.20 ≦2.34 B1 ({fraction (1/10)}) 7.80 6.50 4.50 Ex. 2 ({fraction(9/10)}) ≦2.34 ≦2.34 ≦2.34 7.84 A2 ({fraction (9/10)}) ≦2.34 ≦2.34 ≦2.34B2 ({fraction (9/10)}) ≦2.34 4.15 ≦2.34 Ex. 2 (½) ≦2.34 ≦2.34 ≦2.34 7.84A2 (½) 5.80 ≦2.34 ≦2.34 B2 (½) 7.16 5.44 ≦2.34 Ex. 2 ({fraction (1/10)})3.36 ≦2.34 ≦2.34 7.84 A2 ({fraction (1/10)}) 7.76 7.15 ≦2.34 B2({fraction (1/10)}) 7.81 7.22 5.25 Ex.3 (½) ≦2.34 ≦2.34 ≦2.34 7.83 A3(½) 5.88 3.30 ≦2.34 B3 (½) 7.50 6.20 ≦2.34 Ex. 3 ({fraction (1/10)})3.42 ≦2.34 ≦2.34 7.83 A3 ({fraction (1/10)}) 7.80 7.40 3.27 B3({fraction (1/10)}) 7.82 7.30 5.60 Ex. 4 (½) 3.41 ≦2.34 ≦2.34 7.82 A4(½) 7.30 5.50 4.36 B4 (½) 6.12 4.15 ≦2.34 Ex. 4 ({fraction (1/10)}) 3.31≦2.34 ≦2.34 7.82 A4 ({fraction (1/10)}) 7.79 7.20 5.10 B4 ({fraction(1/10)}) 7.80 6.50 4.50 Ex. 5 ({fraction (1/10)}) 3.29 ≦2.34 ≦2.34 7.83A5 ({fraction (1/10)}) 7.60 7.09 4.27 B5 ({fraction (1/10)}) 7.71 6.413.80

TABLE IVb Viral strain: Adenovirus Product Viral titer, i.e.log([S]_(T=X)) (dilution) T = 0.25 h T = 0.5 h T = 1 h Control T = 1 hEx. 1 ({fraction (9/10)}) ≦2.34 ≦2.34 ≦2.34 7.07 A1 ({fraction (9/10)})4.66 4.35 4.06 B1 ({fraction (9/10)}) 4.41 4.04 3.71 Ex. 1 (½) ≦2.34≦2.34 ≦2.34 7.07 A1 (½) 5.52 4.90 4.71 B1 (½) 2.74 ≦2.34 ≦2.34 Ex. 1({fraction (1/10)}) 2.74 ≦2.34 ≦2.34 7.07 A1 ({fraction (1/10)}) 7.175.98 5.36 B1 ({fraction (1/10)}) 6.26 5.49 5.05

TABLE IVc Viral strain: Poliovirus Product Viral titer, i.e.log([S]_(T=X)) (dilution) T = 0.25 h T = 0.5 h T = 1 h Control T = 1 hEx. 1 ({fraction (9/10)}) ≦2.34 ≦2.34 ≦2.34 8.44 A1 ({fraction (9/10)})6.20 5.49 5.11 B1 ({fraction (9/10)}) 6.12 5.38 4.82 Ex. 1 (½) ≦2.34≦2.34 ≦2.34 8.44 A1 (½) 6.97 6.31 5.72 B1 (½) 6.63 5.47 5.14 Ex. 1({fraction (1/10)}) 3.64 2.81 ≦2.34 8.44 A1 ({fraction (1/10)}) 7.597.40 6.37 B1 ({fraction (1/10)}) 7.41 7.29 6.22

The results in Tables IVa, IVb and IVc show that (i) only thecompositions according to the invention are virucidal at the dilutionsused ({fraction (9/10)}, ½ and {fraction (1/10)}) and for the contacttimes used (0.25 h, 0.5 h and 1 h), and (ii) for a given dilution and agiven contact time, the compositions according to the invention aregenerally more active than the compositions of the prior art.

Experiments IV

Complementary experiments were carried out on experimental farms (on theone hand a banana plantation contaminated by banana canker,Colletotrichum musae, and on the other hand an orchard contaminated byapple canker, Nectria galligena) with the compositions according to theinvention (Ex. 1-Ex. 5) administered by spraying.

This treatment made it possible to save the diseased trees andeffectively to protect the healthy trees.

Other experiments, carried out on harvests stored in silos or smallwooden vats (cereals, tomatoes and dessert grapes in particular), werealso able to demonstrate protection of said harvests from the customarygerms which damage them.

Experiments V

Experiments were carried out with the composition of Example 6 as ahygiene product for the decontamination of balneotherapy baths, usingcustomary hospital bacterial strains (Pseudomonas aeruginosa,Pseudomonas cepacia, Enterobacter agglomerans, Enterobacter cloacae,Escherichia coli, Staphylococcus cohnii, Staphylococcus aureus). It wasfound that, at a final use dilution of {fraction (5/10)}⁷, thecomposition of Example 6 used in this way has an effectivebacteriostatic effect for at least 48 h. At the same final dilution, thecomparative compositions, lacking either the component AgNO₃ or themixture of CH₃CO₂H+CH₃CO₃H, proved ineffective.

The following experiments VI-IX are pollution control experimentscarried out with dilutions of the stock composition of Example 7 and, ifappropriate, the analogous compositions A7 (without AgNO₃) and B7(without the mixture of CH₃CO₂H+CH₃CO₃H).

Experiments VI

Experiments were carried out on soils typical of the mining industry,collected in a stockyard of mining residues belonging to the Canadiancompany IRON ORES, soil no. 1 originating from an abandoned iron pelletworks and soil no. 2 having been taken near a shut-down conveyor. Theeffect of diluting Ex. 7, A7 and B7 on the growth or inhibition of theheterotrophic bacteria extracted from these two soils was evaluated.

The microorganisms were extracted from each soil (5 g) with a sterilesaline solution (50 ml) containing 0.85% w/v of NaCl. The resultingextract was diluted seven times in succession ({fraction (1/10)}dilutions). A volume of 1 ml of the extract and of each dilution wasplaced in a 15 ml test tube containing 8 ml of culture medium (nutrientbroth at a concentration of 8 g/l) and 1 ml of a dilution ({fraction(1/100)}, {fraction (1/10,000)}, {fraction (1/100,000)} or {fraction(1/1,000,000)}) of the composition of Ex. 7, A7 or B7. The tubes wereincubated at 30° C. for 3 days, the control batch receiving no testproduct (i.e. dilution of Ex. 7, A7 or B7).

The results obtained (means of five experiments per test composition andper test dilution) are collated in Table V below.

TABLE V Inhibition of the heterotrophic bacteria Product Totalheterotrophs/g of dry soil (dilution) in soil no. 1 in soil no. 2Controls 5 × 10⁵ 5 × 10⁶ Ex. 7 ({fraction (1/10)}⁶) 5 × 10⁵ 3 × 10⁶ A7({fraction (1/10)}⁶) 5 × 10⁵ 5 × 10⁶ B7 ({fraction (1/10)}⁶) 5 × 10⁵ 5 ×10⁶ Ex. 7 ({fraction (1/10)}⁵) 2 × 10⁵ 2 × 10⁶ A7 ({fraction (1/10)}⁵) 5× 10⁵ 5 × 10⁶ B7 ({fraction (1/10)}⁵) 5 × 10⁵ 5 × 10⁶ Ex. 7 ({fraction(1/10)}⁴) ≦10 10² A7 ({fraction (1/10)}⁴) 10 10⁶ B7 ({fraction (1/10)}⁴)3 × 10⁵ 3 × 10⁶ Ex. 7 ({fraction (1/10)}²) ≦10 ≦10 A7 ({fraction(1/10)}²) 5 × 10³ 6 × 10³ B7 ({fraction (1/10)}²) 8 × 10³ 10⁴

Table V shows that Ex. 7 is very effective at dilutions of {fraction(1/10)}⁴ and {fraction (1/10)}² whereas A7 and B7 are unusable at thesame dilutions.

Experiments VII

Experiments were carried out to study the inhibition of a pure strain ofThiobacillus ferrooxidans (ATCC 13661) in a liquid (NH₄)₂SO₄ mediumcontaining 0.5 g/l of MgSO₄.7H₂O, 0.5 g/l of K₂HPO₄, 33.4 g/l ofFeSO₄.7H₂O and H₂SO₄ (to adjust the pH to 2.2).

1 ml of the suspension of the pure strain of Thiobacillus ferrooxidans(ATCC 13661), 8 ml of the nutrient medium and the dilution of thecomposition of Ex. 7 (at final dilutions of {fraction (1/10)}⁶,{fraction (1/10)}⁵, {fraction (1/10)}⁴ and {fraction (1/10)}³) areintroduced into a test tube. The results obtained (means of 5experiments per dilution) are collated in Table VI below, the controlproduct not containing the dilution of Ex. 7.

TABLE VI Inhibition of Thiobacillus ferrooxidans Product Number ofThiobacillus (dilution) ferrooxidans/100 ml Control 7 × 10⁷ Ex. 7({fraction (1/10)}⁶) 7 × 10⁷ Ex. 7 ({fraction (1/10)}⁵) 5 × 10⁷ Ex. 7({fraction (1/10)}⁴) 10³ Ex. 7 ({fraction (1/10)}³) <10

The results in the Table show that, at the final concentration, Ex. 7 isparticularly effective for inhibiting Thiobacillus ferrooxidans atdilutions of {fraction (1/10)}⁴ and particularly {fraction (1/10)}³. Inthese experiments, the initial bacterial population (7×10⁷ germs/100 ml)was very considerably greater than the bacterial population normallyencountered in soils in the mining industry (10⁴ to 10⁵ germs/l).

Experiments VIII

Experiments were carried out to assess the efficacy of Ex. 7 in theoxidation of cyanides in two soils: a sterilized soil consisting of sandpoor in organic matter, and a sterilized soil consisting of sand andorganic matter (hereafter denoted as “organic soil”). These sterilesoils were contaminated with KCN to give a final concentration of 100 mgof CN− per kg of soil.

CuSO₄ is incorporated as an oxidation catalyst into a dilution({fraction (1/1000)}, {fraction (1/100)} or {fraction (1/10)}) of thecomposition of Example 7 (so as to give a final concentration of 20 mgof Cu²⁺per kg of soil). 5 ml of each dilution of Ex. 7, complementedwith Cu²⁺, are added to 100 g of contaminated soil, the final dilutionof Ex. 7 being 0.005, 0.5 or 5 ml of Ex. 7 per kg of soil. The soilstreated in this way are left to stand for 4 h at room temperature(10-25° C.), after which the cyanide concentration remaining in eachsoil is measured.

The results obtained have been collated in Table VII below.

TABLE VII Cyanides remaining in the soils Ex. 7 Total cyanides remaining(mg/kg) (ml/kg) sand organic soil 0 27 ± 2 10 ± 0.5 0.005 21 ± 7 8.5 ± 10.5 3 ± 0.2 8.1 ± 0.5 5 — 4.3 ± 1.2

The results in Table VII show that the cyanide concentrations in theuntreated soils were found to be lower than the initial concentrationincorporated. This explains that other cyanide-eliminating mechanismshave taken place (atmospheric oxidation, evaporation, etc.). Saidresults further show that the cyanide concentration remaining in theorganic soil is lower than that remaining in the sand, which isexplained (i) by the fact that the pH of the sand (6.8) is differentfrom that of the organic soil (7.4), a basic environment being morefavorable to the oxidation of cyanides, and (ii) by the fact that theorganic matter was able to oxidize the cyanides.

Experiments IX

Complementary experiments were carried out to assess whether or not thecleaning composition according to the invention, which inhibits thestrains of Thiobacillus ferrooxidans, has an unfavorable effect asregards acid generation because of the presence of H₂O₂.

A sludge originating from a waste water treatment plant, containing ahigh population of Thiobacillus ferrooxidans and having a solids contentof 20% w/v, was acidified to pH 4.0 with sulfuric acid. 75 ml samples ofthis sludge were placed in 250 ml flasks. Half of these flasks weresterilized to kill the bacteria present. 5 ml of various dilutions ofEx. 7 were then introduced into each flask to give final dilutions of{fraction (1/10)}⁶, {fraction (1/10)}⁵, {fraction (1/10)}⁴, {fraction(1/10)}³ and {fraction (1/10)}². All the flasks were shaken (orbitalshaker at 150 rpm) at 28° C. for 4 days. The pH was then measured ineach flask.

The results obtained (means of 2 experiments) have been collated inTable VIII below.

TABLE VIII Evaluation of pH of sludges pH in sterile sludges pH insludges containing (without Thiobacillus Thiobacillus Dilution of Ex. 7ferrooxidans) ferrooxidans 0 3.3 2.6 {fraction (1/10)}⁶ 3.3 2.7{fraction (1/10)}⁵ 3.3 2.7 {fraction (1/10)}⁴ 3.3 2.9 {fraction (1/10)}³3.2 3.0 {fraction (1/10)}² 2.7 2.7

As regards the sludges not containing Thiobacillus ferrooxidans(sterilized sludges), the results in Table VIII show that (i) the pH ofthe sludges decreased from 4.0 to 3.3 in the absence of Ex. 7,indicating that chemical reactions, such as the natural oxidation ofFe²⁺ by atmospheric oxygen, have taken place, (ii) at a final dilutionless than or equal to {fraction (1/10)}⁴, Ex. 7 has no influence on thepH, and (iii) at a dilution of {fraction (1/10)}², on the other hand,Ex. 7 induces acid generation.

As regards the sludges containing Thiobacillus ferrooxidans, the resultsin Table VIII show that (i) with the exception of Ex. 7 at a finaldilution of {fraction (1/100)}, the pH dropped to lower values thanthose measured in the previously sterilized samples for an identicalconcentration of Ex. 7, indicating a growth of Thiobacillusferrooxidans, (ii) the pH drops in proportion with the concentration ofEx. 7 (i.e. the number of bacteria decreases when the concentration ofEx. 7 increases), and (iii) at a final dilution of {fraction (1/100)},Ex. 7, which should prevent the pH from dropping, induces acidgeneration.

In conclusion, the result of these experiments is that Ex. 7 has to beused at a final dilution of less than {fraction (1/100)} in order toavoid the effect of acid generation, a final dilution of 1/1000 beingperfectly suitable.

Synergistic Effect

The interaction of the combination of H₂O₂+silvercomponent+CH₃CO₂H/CH₃CO₃H mixture was assessed using the methoddescribed by R. F. SCHINAZI et al., Antimicrob. Agents Chemother., 22(no. 3), pages 499-507 (1982), and improved by J. C. POTTAGE, ibidem, 30(no. 2), pages 215-219, (1986), and in WO-A-91/13626, taking thefollowing definitions into account:

IT_(S)=infectious titer of the stock of strains used,

IT_(A)=infectious titer of product A (in this case H₂O₂+CH₃CO₂H/CH₃CO₃Hmixture) brought into contact with said stock,

IT_(B)=infectious titer of product B (in this case H₂O₂+silvercomponent) brought into contact with said stock,

T_(AB)=infectious titer of product A+B (in this caseH₂O₂+CH₃CO₂H/CH₃CO₃H mixture+silver component) brought into contact withsaid stock,

S=logIT_(S),

A=logIT_(A),

B=logIT_(B),

C=logIT_(AB),

Y_(A)=A/S=logIT_(A)/LogIT_(S),

Y_(B)=B/S=logIT_(B)/logIT_(S),

Y_(AB)=C/S=logIT_(AB)/logIT_(S), and

Y_(C)=product of Y_(A)×Y_(B).

There is a synergistic effect if Y_(AB)≦Y_(C).

On the basis of these definitions, when the values given in Table IVaare taken, for example, the comparison of the values of Y_(AB) and Y_(C)given in Table IX below is obtained.

Said Table IX shows that, at a final dilution of 1/10, the mixture ofessential constituents of Ex. 1-Ex. 5 has a synergistic effect relativeto A1-A5 and B114 B5, respectively, towards the viral strain oforthopoxvirus since Y_(AB) is less than or equal to Y_(C).

TABLE IX Synergistic effect towards Orthopoxvirus at a dilution of 1/10Products S A B C Y_(A) Y_(B) Y_(AB) Y_(C) Ex. 1, A1, B1 7.82 7.60 7.80≦2.34 0.97 0.99 ≦0.29 0.96 (T = 0.25 h) Ex. 2, A2, B2 7.84 7.76 7.813.36 0.98 0.99 0.42 0.97 (T = 0.25 h) Ex. 3, A3, B3 7.83 3.27 5.60 ≦2.340.41 0.71 ≦0.29 0.29 (T = 1 h) Ex. 4, A4, B4 7.82 7.20 6.50 ≦2.34 0.920.83 ≦0.29 0.76 (T = 0.5 h) Ex. 5, A5, B5 7.83 7.09 6.41 ≦2.34 0.90 0.81≦0.29 0.72 (T = 0.5 h)

What is claimed is:
 1. An aqueous decontaminating composition having atotal weight, wherein the composition comprises: (A) an amount of H₂O₂less than or equal to 60% by weight, based on the total weight of saidcomposition; (B) an amount of an RCO₃H/RCO₂H mixture, where R is methylor ethyl, wherein there is a weight ratio of said mixture to thehydrogen peroxide, wherein the weight ratio of said mixture to thehydrogen peroxide is between 0.15/1 and 0.85/1; (C) an amount of asilver component as a source of Ag⁺ ions, wherein the silver componentis selected from the group consisting of silver salts and complexes,wherein there is a weight ratio of said silver component to the hydrogenperoxide, wherein the weight ratio of said silver component to thehydrogen peroxide is between 0.0005/1 and 0.015/1; (D) an amount of astabilizer, wherein there is a weight ratio of said stabilizer to thehydrogen peroxide, wherein the weight ratio of said stabilizer to thehydrogen peroxide is between 0.0005/1 and 0.025/1; and an amount ofwater to make up to 100% by weight.
 2. A composition according to claim1 which also comprises at least one component selected from the groupconsisting of (E) a surfactant; (F) a corrosion inhibitor; and (G) afragrance.
 3. A composition according to claim 1 wherein the weightratio of the silver component to the hydrogen peroxide is between0.0008/1 and 0.005/1.
 4. A composition according to claim 1 wherein theweight ratio of the stabilizer to the hydrogen peroxide is between0.0008/1 and 0.005/1.
 5. A composition according to claim 1 which alsocomprises (E) an amount of a surfactant, wherein there is a weight ratioof said surfactant to the hydrogen peroxide, wherein the weight ratio ofsaid surfactant to the hydrogen peroxide is between 0.00005/1 and0.01/1; (F) an amount of a corrosion inhibitor, wherein there is aweight ratio of said corrosion inhibitor to the hydrogen peroxide,wherein the weight ratio of said corrosion inhibitor to the hydrogenperoxide is between 0.00005/1 and 0.03/1; and/or (G) a fragrance in anamount less than or equal to the amount of said corrosion inhibitor. 6.A composition according to claim 1 wherein the amount of H₂O₂ is 1.5 to8% by weight of the total weight of the composition; wherein the amountof the RCO₃H/RCO₂H mixture is 0.75 to 5.6% by weight of the total weightof the composition; wherein the amount of the silver component is 0.0012to 0.04% by weight of the total weight of the composition; wherein theamount of the stabilizer is 0.0012 to 0.04% by weight of the totalweight of the composition.
 7. A composition as claimed in claim 6further comprising: (E) an amount of a surfactant wherein the amount ofsaid surfactant is 0.0075 to 0.04% by weight of the total weight of thecomposition; (F) an amount of a corrosion inhibitor wherein the of saidcorrosion inhibitor is 0.003 to 0.04% by weight of the total weight ofthe composition; and/or (G) a fragrance.
 8. A composition as claimed inclaim 1, wherein the amount of H₂O₂ is 7.5-8% by weight of the totalweight of the composition; and wherein the RCO₃H/RCO₂H mixture comprisesan amount of a mixture of CH₃CO₃H and CH₃CO₂H, wherein the amount of themixture of CH₃CO₃H and CH₃CO₂H is 4.5 to 4.8% by weight of the totalweight of the composition.
 9. A composition as claimed in claim 1further comprising: (E) an amount of a surfactant wherein a weight ratioof said surfactant to the hydrogen peroxide is 0.005/1; (F) an amount ofa corrosion inhibitor wherein a weight ratio of said corrosion inhibitorto the hydrogen peroxide is between 0.001/1 and 0.005/1; and/or (G) afragrance in an amount less than or equal to the amount of saidcorrosion inhibitor.
 10. A method for preparing the decontaminatingcomposition claimed in claim 1, the method comprising: preparing aresulting mixture by mixing sufficient amounts of the water, the silvercomponent, the stabilizer, the hydrogen peroxide, and an acid substanceselected from the group consisting of RCO₃H, RCO₂H, and mixturescomprising RCO₃H and RCO₂H, wherein the resulting mixture is thedecontaminatine composition claimed in claim
 1. 11. A method as claimedin claim 10, wherein the method further comprises allowing anequilibrium H₂O₂+RCO₂H←→RCO₃H+H₂O to be established in the resultingmixture.
 12. A composition according to claim 1 wherein the amount ofH₂O₂ is 7.5-8% by weight of the total weight of the composition; whereinthe RCO₃H/RCO₂H mixture comprises an amount of a mixture of CH₃CO₃H andCH₃CO₂H, wherein the amount of the mixture of CH₃CO₃H and CH₃CO₂H is 4.5to 4.8% by weight of the total weight of the composition; wherein thesilver component comprises an amount of AgNO₃, wherein the amount ofAgNO₃ is 0.008% by weight of the total weight of the composition; andwherein the stabilizer comprises an amount of H₃PO₄, wherein the amountof H₃PO₄ is 0.008% by weight of the total weight of the composition. 13.A method for preparing an aqueous decontaminating composition as claimedin claim 12, said method comprising the following steps: (1°) providingan aqueous solution comprising the AgNO₃; (2°) preparing a firstresulting solution by introducing into the aqueous solution of AgNO₃ anaqueous solution of phosphoric acid comprising the H₃PO₄, wherein theH₃PO₄ is 85% by weight of the aqueous solution of phosphoric acid; (3°)preparing a second resulting solution by introducing the first resultingsolution at a rate of between 3 and 6 l/hr into an aqueous solution ofhydrogen peroxide comprising the hydrogen peroxide, wherein the H₂O₂ is50 to 60% by weight of the aqueous solution of the hydrogen peroxide,with stirring, at a temperature of between 0° C. and 25° C.; (4°)preparing a third resulting solution by introducing an acid substancecomprising the CH₃CO₂H at a rate of between 3 and 6 l/h into the secondresulting solution, with stirring, at a temperature of between 0° C. and25° C.; (5°) leaving the third resulting solution to stand for 48 h in adark area at a temperature of between 0° C. and 25° C. so that anequilibrium H₂O₂+CH₃CO₂H←→CH₃CO₃H+H₂O is established; and (6°) addingwater to make up to 100% by weight of the composition; whereinsufficient amounts of the H₂O₂, the CH₃CO₂H, the AgNO₃, and the H₃PO₄are provided and/or introduced to yield the aqueous decontaminatingcomposition claimed in claim
 12. 14. A method as claimed in claim 13,wherein the temperature in step (3°) is between 4° C. and 15° C.;wherein the temperature in step (4°) is between 4° C. and 15° C.; andwherein the temperature in step (5°) is between 4° C. and 15° C.
 15. Amethod for preparing an aqueous decontaminating composition as claimedin claim 12, said method comprising the following steps: (1°) providingan aqueous solution comprising the AgNO₃; (2°) preparing a firstresulting solution by introducing into the aqueous solution of AgNO₃ anaqueous solution of phosphoric acid comprising the H₃PO₄; (3°) preparinga second resulting solution by introducing the first resulting solutioninto an aqueous solution of hydrogen peroxide comprising the hydrogenperoxide, wherein the H₂O₂ is 50 to 60% by weight of the aqueoussolution of the hydrogen peroxide; (4°) preparing a third resultingsolution by introducing an acid substance comprising the CH₃CO₂H intothe second resulting solution; (5°) allowing the third resultingsolution to stand until an equilibrium H₂O₂+CH₃CO₂H←→CH₃CO₃H+H₂O isestablished; and (6°) adding water to make up to 100% by weight of thecomposition; wherein sufficient amounts of the H₂O₂, the CH₃CO₂H, theAgNO₃, and the H₃PO₄ are provided and/or introduced to yield the aqueousdecontaminating composition claimed in claim
 12. 16. A method ofpreparing an aqueous decontaminating composition according to claim 1,said method comprising the following steps: (1°) providing an aqueoussolution comprising the silver component; (2°) introducing thestabilizer into said aqueous solution to yield a first resultingsolution; (3°) preparing a second resulting solution by introducing saidfirst resulting solution into a hydrogen peroxide solution comprisingthe hydrogen peroxide or by introducing the hydrogen peroxide solutioninto said first resulting solution; (4°) preparing a third resultingsolution by introducing into said second resulting solution an acidsubstance selected from the group consisting of RCO₃H, RCO₂H, andmixtures comprising RCO₃H and RCO₂H; (5°) leaving said third resultingsolution until an equilibrium H₂O₂+RCO₂H←→RCO₃H+H₂O has beenestablished; and (6°) making up to 100% by weight with water; whereinsufficient amounts of the silver component, the stabilizer, the hydrogenperoxide, and the acid substance are provided and/or introduced to yieldthe aqueous decontaminating composition claimed in claim
 1. 17. A methodfor decontaminating an industrial mining site, the method comprisingadding to the industrial mining site an amount of a decontaminatingcomposition as claimed in claim 1 in order to reduce acid generationand/or to destroy cyanides.
 18. A method for decontaminating a portionof an item, the method comprising applying to the portion of the item aneffective amount of the decontaminating composition claimed in claim 1.19. A method as claimed in claim 18, wherein the item is selected fromthe group consisting of spaces, surfaces of materials, instruments,foodstuffs, harvests, outdoor crops, greenhouse crops, storagecontainers, pipelines, and drinking water.
 20. A method as claimed inclaim 18, wherein the portion of the item is dried after thedecontaminating composition is applied.